<!DOCTYPE html>
<style>
iframe {
    position: absolute;
    width: 200px;
    height: 200px;
    top: 100px;
    left: 100px;
    border: solid green 50px;
}
</style>
<iframe src="data:text/html,%3Cspan%3EJust%20a%20simple%20little%20iframe.%3C%2Fspan%3E">
